1. Technical Field
The disclosure relates to a microphone device.
2. Description of Related Art
Currently, various microphones are used in many applications, such as telephones, tape recorders and cell phones, for example.
A typical microphone device includes a light emitting unit, a light receiving unit and a vibrating membrane. The light emitting unit emits light beams to the vibrating membrane, and then the vibrating membrane reflects the light beams to the light receiving unit. When affected by a sound wave, the vibrating membrane moves back and forth in response to the sound wave to vary incident angles of the light beams, such that the amount of light beams collected by the light receiving unit varies correspondingly. The light receiving unit generates an electrical signal via detecting the varying of the amount of collected light beams. Finally, the electrical signal is processed and converted into an audio signal. In order to prevent the light beams from being transmitted to the light receiving unit directly, a nontransparent plate is positioned between the light emitting unit and the light receiving unit, however, such structure complicates the structure of the typical microphone device.
Therefore, a new microphone device is desired to overcome the above-described shortcoming.